OSD soars: Advancements in oral solid dose

Aug. 8, 2023
In this initial installment of our exploration into the history and evolution of oral solid dose drugs, we take a look at the transformative path from ancient pills to the future of medicine.

The compressed form of today’s oral solid dose (OSD) medications can be attributed to a 19th century artist’s desire to improve upon a commonly used tool.

But the tale of tablets goes back much further. Around 1500 B.C., ancient Egyptians first documented the use of pills, crafted from a combination of bread dough, honey or grease blended with medicinal ingredients. These medicines were later coined as ‘pilula’ by the Roman scholar Pliny the Elder, referring to what we now recognize as pills.

Throughout history, the challenge of swallowing pills has spurred numerous efforts to enhance their ease of consumption. In medieval times, drugs were coated with slippery plant substances. Gilding them in gold and silver was also common, although often rendering them ineffective as they passed through the digestive tract.

In 1843, British artist and inventor William Brockedon, seeking to develop a more efficient way to produce pencil lead, patented a method of compressing pure black lead powder into solid compact blocks. His goal was to better utilize the dust and debris from the pencils he regularly used, but instead, his invention gave a makeover to available methods to shape pills and lozenges.

Brockedon’s invention enabled the compressed tablet, which quickly overshadowed dosed powders, offering a new level of convenience, precise dosage and improved palatability.

Compressed tablets also offered better storage stability and easier identification, improving medication handling and compliance.

OSD drugs — which include tablets, capsules, softgels and other solid formulations designed to be swallowed and dissolved in the gastrointestinal tract — have since become the backbone of the pharmaceutical industry. They serve as the primary means of drug administration for approximately 84% of all medications.

While OSD has earned its place as the industry’s most trusted drug delivery tool, manufacturers continue to look for new ways to help it soar. Recent technological advancements have ushered in an era of renewal for OSDs, offering fresh possibilities to enhance the dosage’s efficacy and improve the patient experience.

Today’s pharma manufacturers are enabling an OSD metamorphosis — leveraging the potential of fixed-dose combinations and embracing the power of digitization and 3D printing — to transform drug delivery.

Staying consistent

OSD products have enjoyed a considerable run as the preferred formulation of drugmakers and patients — but if the dosage form wants to remain on top, drugmakers need to continue to address its shortcomings.

A primary objective when manufacturing tablets and capsules, the most common forms of OSD products, is to establish a formulation that ensures each dose is consistent. This involves achieving a repeatable distribution of ingredients, as well as uniformity in dissolution and bioavailability.

But this level of consistency has historically proven challenging, and as small molecule formulations become more potent and more complex, overcoming bioavailability and solubility issues has become more difficult. Poorly soluble formulations do not dissolve quickly or fully in gastrointestinal fluids, reducing the drug’s bioavailability, or its ability to be absorbed and used by the body.

“Complex formulations or potent drugs may require specialized equipment and optimized processes to maintain product integrity, uniformity and dosage accuracy,” says Rafael Costa, vice president of sales for the Americas region at ACG Capsules. “Developing a stable and bioavailable reformulation with the desired release profile can be particularly challenging when formulating drugs for encapsulation.”

Hard capsules are favored for new medicines in clinical trials as they eliminate the need for costly formulation development and allow for the delivery of multiple drugs in a single capsule.  Additionally, hard capsules generally require fewer manufacturing steps, which enables faster product development.

To meet a growing encapsulation need, ACG Capsules, one of the world’s largest producers of empty hard-shell capsules, has focused on staying at the forefront of capsule innovation. In 2020, ACG revealed its new line of hydroxypropyl methyl cellulose (HPMC) capsules which exhibit dissolution properties comparable to those of gelatin capsules. They also have inherently low moisture content which allows for the encapsulation of ingredients that are sensitive to moisture.

Read phase II: Evolution of oral solid dose technology

About the Author

Andrea Corona | Senior Editor

Andrea Corona serves as the Senior Editor of Pharma Manufacturing — a leading source of news and insights for pharma professionals — and is responsible for creation of editorial content, moderating webinars, and co-hosting the "Off script" podcast. Her editorial journey started as an as associate editor at Biocompare, an online platform providing product information, industry news, articles, and other resources to support scientists in their work. Before Biocompare, she was a digital producer at Science Friday, focusing on adapting radio segments for the web and social media management. Andrea earned her bachelor's degree in journalism and biology from the State University of New York, at Purchase College.